/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.skywalking.apm.agent.core.context.status;

import lombok.Getter;
import org.apache.skywalking.apm.agent.core.boot.BootService;
import org.apache.skywalking.apm.agent.core.boot.DefaultImplementor;
import org.apache.skywalking.apm.agent.core.conf.Config;
import org.apache.skywalking.apm.util.StringUtil;

import java.util.Arrays;

import static org.apache.skywalking.apm.agent.core.context.status.StatusChecker.HIERARCHY_MATCH;
import static org.apache.skywalking.apm.agent.core.context.status.StatusChecker.OFF;

/**
 * The <code>StatusCheckService</code> determines whether the span should be tagged in error status if an exception
 * captured in the scope.
 * <p>
 * StatusCheckService确定如果范围内捕获异常，是否应将跨度标记为错误状态。状态检查服务
 * <p>
 * 状态检查服务
 *
 * 用来判断那些异常不算异常
 */
@DefaultImplementor
public class StatusCheckService implements BootService {

    @Getter
    private String[] ignoredExceptionNames;

    /**
     * 枚举
     */
    private StatusChecker statusChecker;

    @Override
    public void prepare() throws Throwable {

        // 一条链路如果某个环节出现了异常,默认情况会把异常信息发送给OAP,在SkyWalking UI中看到链路中那个地方出现了异常,方便排查问题
        // Config.StatusCheck.IGNORED_EXCEPTIONS. 不应该当做错误的异常
        // ignoredExceptionNames 需要忽略的异常
        ignoredExceptionNames = Arrays.stream(Config.StatusCheck.IGNORED_EXCEPTIONS.split(","))
                                      .filter(StringUtil::isNotEmpty)
                                      .toArray(String[]::new);

        // 检查异常时的最大递归程度
        // AException
        //  BException
        //   CException
        // 如果IGNORED_EXCEPTIONS配置的是AException,此时抛出的是CException需要递归找一下是否属于AException的子类
        statusChecker = Config.StatusCheck.MAX_RECURSIVE_DEPTH > 0 ? HIERARCHY_MATCH : OFF;
    }

    @Override
    public void boot() throws Throwable {

    }

    @Override
    public void onComplete() throws Throwable {

    }

    @Override
    public void shutdown() throws Throwable {

    }

    /**
     * 去检查
     *
     * @param e
     * @return
     */
    public boolean isError(Throwable e) {
        return statusChecker.checkStatus(e);
    }
}
